Buffing pad cushion having passages for circulating cooling air through the cushion to the buffing pad



F. DE MICHEL Sept. l, 1953 BUFFING PAD CUSHION HAVING PASSAGES FOR CIRCULATING COOLING AIR THROUGH THE CUSHION TO THE BUFFING PAD Filed D60. l2, 1947 2 Sheets-Sheet 1 Sept. l, 1953 F, DE MlCHEL 2,650,385

BUFFING PAD CUSHION HAVING PASSAGES FOR CIRCULATING COOLING AIR THROUGH THE CUSHION TO THE BUFFING PAD Filed DGO. 12, 1947 2 Sheets-Sheet 2 Patented Sept. 1 195-3 OFFICE BUFFING PAD CUSHION HAVING PAS'- S'AGES FOR CIRCULATING COOLING AIR THROUGH THE CUSHION TO THE BUFFING PAD Frank De Michel, Chicago, Ill.

Application December 12, 1947, Serial No. 791,302

My invention relates to an improvement iny 4cushions for power driven buftlng pads and more specifically to the provision of means for cooling such a pad and cushion.

The destructive qualities of lheat incident to bufling operations both on the pad and on the work are well known, and one object of my invention, therefore, is to provide a novel cushion for a builing pad which reduces the accumulation of frictional heat generated in buf'ling.

Another object of my invention is to provide a novel means for air cooling a cushion for a buiiing pad so that the cushion may be made of sponge rubber which is ideally suited for this purpose other than in resistance to heat.

Other objects and advantages of my invention will appear from the following description anzi drawings, in which:

Fig. 1 is a top plan view of the cushion overlaid in part with a section of a bufngrpad and broken away in part to illustrate other pad details and the structure of the cushion;

Fig. 42 is a vertical sectional 4view which may be considered as being taken substantially along the line 2-2 of Fig. l looking in the direction of therarrows;

Fig. 3 is a horizontal sectional view of a modication of my invention which may be considered as being taken substantially along the line 3-3 of ig. 4 looking in the direction of the arrows; an

Fig. 4 is a vertical sectional view of thi-s modification which may be considered as being taken substantially along the line 4-4 of Fig. 3 looking in the direction of the arrows.

My invention comprises primarily a hub member I8, a cushion I2, and a .nut I4.V The hub member I is an approximately conical member having a widely flared 'base which provides a large bearing surface IB against which the cushion rides. hub and is adaptedto fit loosely around the threaded end 20 of a rotatable power driven 'shaft 22. The cushion I2 has a flexible laminated base 24 having a plurality of members 'which vmay be made of thin ilexible steel, 'phenolic sheets, or vother suitable materials. The 'upper member 42li may have a downwardly dshed 'edge 28 to afford greater support to the edges of the cushion. The laminations may be secured together by rivets 8U or any other suitable means.

A sponge rubber cushion is bonded to the upper surface of the base 24 extending down over the idished edge 28. The upper side of the cushion has a series of sponge rubber elevations 34 formed thereon which serve to support the pad 36 and at the saine time define Aair .passages 38 through which air may circulate. V14s here shown, -the'ele- An axial opening I8 is formed in the I vations consist of a, separated inner 40 and outer 42 series of Wedge shaped ribs extending radially outwardly from the center of the cushion. However, there are many forms which the passages may take. The preferred structure would provide for intercommunication of the passages and some connection with a, central hole or cavity 44. To insure simultaneously sufficient air passages and sufficient support, the elevations and passages should be closely spaced. I accom- )plish this by providing for the two series of ribs eparated by the passa-ges "45. Other designs are f course possible. 'I'he rubber cushion has the hole 44 passing centrally therethrough, a circu- 5 lar cavity 46 concentric with and opening into the hole 44 formed therein 'in which the nut I4 is seated to secure the pad to the shaft 22, and slits 48 opening into the hole andextending up- 'ward from the cavity to the surface of the pad whereby the nut may be inserted into the cavity.

i The nut I4 is similar to that found in the sandiing machine art and consists of a tubular mem- `ber threaded internally to engage the portion 20 of the shaft 22 and adapted to iit between this portion and. the axial opening I8 in the hub I0. On its upper end it bears a wide circular flange 52 which locks the pad between it and the surface f' I6 of the hub.

The bufling pad I prefer to employ with this 'cushion comprises a sheepskin disk 54 covered with fleece v56 having a drawstring sheath 58 secured to the perimeter thereof and a drawstring 80 therein. The pad has a central aperture 62 formed therein with a stiff reinforcing piece 64 surrounding the aperture to strengthen its Walls. The hole 44 and the aperture -62 are arranged to fall into communicating relation when the pad is placed on the cushion.

The circulation of air within and into and out of the cushion pad is accomplished by the bumng operation. When the spinning buffer is -pressed against a surface the elevations 34 at the point of contact will be compressed, lessening the total yair capacity of the unit. Hence, some air will be forced out through vhole 44 and aperture '62. As 45 the buier rotates the elevations will be successively depressed and released and the air in the successive passages will pulsate in and out. This incessant motion will result in a continuous turbulence which will hasten the movement ofthe 50 air between various parts of the ldevice and accelerate the interchange of the heated air for cool air at the orifice 62. vUpon a change of the pressure on the buffer the unit 'will breathe in or out and when the buffer 'is removed from the 55 vwork lcool air will re-enter to replace the initially displaced air.

The modified formofanv invention illustrated in Figs. 3 and 4 resembles closely the basic form. It' employs the same hub 10, nut 12 and laminated base 14. It may be used with the same type pad 16. having the orice 18. The cushion 80 is again formed of' a resilient material, such as sponge rubber, and has a central opening 82 with slits 84 extending outwardly therefrom to provide for the insertion of the nut 12.

The main point of difference rests in the air passage structure. On the upper surface 8B of the cushion a plurality of relatively large ports 88 are formed in the rubber cushion which ex- 90 are formed on the underside thereof into which the ports open. The radial passages are .interconnected by an annular passage 92. Here zagain, the configuration of holes and passages imay be varied Without departing from the spirit of my invention. The objectives to be achieved are adequate support, closely spaced cooling ports and interconnecting means providing a unitary system. Also, it is desirable that the system be open to the exterior. In this form of the invention the annular passage 92 denes an annular recess 94 about the opening 82 whereby the nut flange 96 may be accommodated between the back 14 and the cushion without causing the central port of the surface of the cushion to bulge. The iloor of this recess is grooved to pro-l vide other radial passages 98, furnishing com-1L munication between the annular passage 92 and? the opening 82.

The rubber cushion is bonded to the base be It will be noted here Vthat the nut flange ma tween the passages 90 and outside the recess 9431 bear directly on the back without the interposi-= tion lof any cushion material.

The principle of operation of this modification is the same as that of the first form. Variations in pressure during the buiiing operation vary the air capacity to produce a breathing ofv the cushion andthe local pressure change within the cushion at constant bulng pressure causes the pulsation of the air, both contributing to the cooling effect as above described.

Having described my invention, what I claim! as new and useful and desire to secure by Letters,

Patent of the United States is:

1. A cushion for a bufiing pad adapted to be connected 4to a rotatable shaft and. to have mounted thereon a buing pad of the type which* encloses the face and periphery of the cushion and which has a small central hole formed therein, said cushion being formed of a spongy easily compressible rubber so that it is locally compressible by bufiing pressure, said cushion being formed with air passages therein open to the cushion face normally covered by the pad, and said cushion being formed with a central cavity therein with which the small central hole falls into alignment when the pad is mounted on the cushion, said cavity communicating with said passages, whereby local compression of said cushion under buihng pressure as said cushion and pad are rotated causes circulation of air through said passages, cavity and hole to effect cooling of said cushion and pad.

2. A cushion for a bufiing pad adapted to be connected to a rotatable shaft and to have a buing pad of the type which encloses the face and periphery of thecushion and which has a small central hole formed therein mounted thereon, said cushion being formed of a spongy easily compressible rubber so that it is locally compressible by bufling pressure, said cushion being .4 formed with a plurality of generally radially disposed air passages therein open to the cushion face normally covered by the pad, and said cushion being formed with a central cavity therein with which the small centralhole falls into alignment when the pad is mounted on the cushion. said cavity communicating with the inner ends of said passages, whereby local compression of said cushion under buiiing pressure as said cushion and pad are rotated causes circulation of air through said passages, cavity and hole to eiect cooling of said cushion and pad.

3. A cushion for a bung pad adapted to be connected to a rotatable shaft and to have a bufiing pad of the type which encloses the face and periphery of the cushion and which has a small central hole formed therein mounted thereon, said cushion being formed of a spongy easily compressible rubber so that it is locally compressible by Ibufling pressure, said cushion being formed with a plurality of generally radially disposed air passages therein open throughout their lengths to the cushion face normally covered by the pad, and said cushion being formed with a central cavity therein with which the small central hole falls into alignment when the pad is mounted on the cushion, said cavity communicating with the inner ends of said passages, whereby local compression of said cushion under bufiing pressure as said cushion and pad are rotated causes circulation of air through said passages, cavity and hole to effect cooling of said cushion and pad.'Y

4. A buiiing device adapted to be mounted on a rotatable shaft comprising a cushion formed of a thick spongy easily compressiblel rubber whichis deformable and compressible by buing pressure, a central cavity formed in said cushion and open to the face thereof, a pluralityof generally radiallyextending grooves formed in the face of said cushion and opening into said cavity at their inner ends, and a bufiing pad mounted on said cushion to'enclose' the face and periphery thereof andl having a small central hole therein aligned with said cavity, said grooves, cavity and said pad defining a system of air passages which are locally changed volumetrically by local compression of said cushion during the buing operation to produce a pulsating move-.

References lCited in the 111e of this patent UNITED VSTATES PATENTS Number Name Date 384,076 Riedell June 5, 1888 505,644 Webster Sept. 26, 1893 617,233 De Wolfe Jan. 3, 1899 1,765,808 Tone June 24, 1930 1,862,103 Stratford June 7, 1932 2,028,874 Kramer et al. Jan. 28, 1936 2,114,967 Myers Apr. 19, 1938 2,119,738 Dempsey June 7, 1938 2,189,472 Peterson Feb. 6, 1940 2,257,864 Sheehan Oct. 7, 1941 2,294,064 Amstuz Aug. 25, 1942 2,309,819 Benner, Feb. 2, 1943 2,334,642. Moore Nov. 16, 1943 2,410,812 De Michel -Nov. 12, 1946 2,478,074 Atkin Aug. 2, 1949 2,527,762 Pratt Oct. 31, 1950 2,542,158 Soderberg Feb. 20, 1951 2,573,411 De Michel Oct. 30, 1951 

